Re: [linux-lvm] LVM and snapshot performance

From: Alasdair G Kergon <agk redhat com>

To: "Wayne H. Badger" <badger yahoo-inc com>

Cc: linux-lvm redhat com

Subject: Re: [linux-lvm] LVM and snapshot performance

Date: Fri, 16 Jan 2009 22:36:50 +0000

1. You don't say what filesystem/journal configuration is involved.
2. Is it a system where you can run test kernels or is it too 'live' for that?
3. Try all the syncing and cache flushing options before issuing the lvremove.
4. Could it depend on the amount of io load over a short period before the
lvremove runs, rather than something cumulative?
5. What more can you find out from ps/iostat/sysrq/lvm logging about what the
system is doing during the lvremove?
6. What devices/drivers are involved in the stack? (We had a perhaps-related
issue show up with loop.)
Alasdair
--
agk redhat com